The definition of residential dwelling units in the ADA and TAS are:

106.5.54 Residential Dwelling Unit. A unit intended to be used as a residence that is primarily longterm in nature. Residential dwelling units do not include transient lodging, inpatient medical care, licensed long-term care, and detention or correctional facilities. 

Per the Department of Justice the following facilities will be considered residential and must meet the scoping (233)  and technical standards (809):

Social Service Center Establishments. Group homes, halfway houses, shelters, or similar social service establishments that provide either temporary sleeping accommodations or residential dwelling units 

Apartments or townhouse facilities that are provided by or on behalf of a place of education, which are leased on a year-round basis exclusively to graduate students or faculty and do not contain any public use or common use areas available for educational programming.  These include RA's, dorm directors and graduate student and faculty housing.

In Texas, TDLR also requires that in Emergency Response buildings and facilities like Fire Stations, the sleeping and living quarters exclusively used by the fire fighters or EMTs are considered "residential"

The ADA Standards have several places where residential facilities are described.  The following give you a summary of what is required.  The ADA sections are provided for further reading

Section 233 outlines the requirements for residential dwelling units (as defined above):

1) The number of new units required to follow the technical standards are based on the total number of units.  

a) If you have 15 or less, 100% of units must comply, 

b) In facilities with 16 or more units: 

•   5% but no less than one must provide mobility features and be on an accessible route, including that all doors must meet the requirements of 404 

• 2% but no less than one communication features (including two way communication per 708 and fire alarms per 702)

• units should be dispersed.

2) In alterations and additions, the requirements only apply if there aren't enough units to begin with and the new one's would increase the number required.  

3) Only the parts of the residential facility that requires access will have to be on an accessible route, including multi story buildings where the mobility feature rooms are on the lower floors, then the non-mobility rooms on the upper floors will not require an accessible route.

In multi-story facilities where the residential portion is located in floor above or below the ground level, Limited Use Limited Application elevators [408LULA Elevators] or Residential Elevators [409], are allowed to be used.

4) Parking for residents:

a) If parking is assigned per unit, the mobility feature unit must have accessible parking provided. They do not need signage but must be on the shortest route to the entrance. 

b) If more than one parking space is assigned per unit, then 2% must be accessible

c) non-resident parking will have to meet the requirements for parking and table 208.2

Stadards for residential dwelling units are found in section 809:

1) One accessible route within the unit shall be provided.

2) All rooms with mobility features must have a turning space.

3) Kitchens must follow requirements of section 804 (including distance between counters, 30" wide knee space for work surface, 34" counters at sinks etc.)

4) At least one bathroom must comply with 603.  There are several exceptions for residential facilities and they are listed below:

a) At non-residential restrooms a lavatory cannot overlap the clear floor space of a water closet, but in a residential dwelling unit is allowed if it follows Figure 604.3.2

c) Grab bars or shower seats are not required to be installed in toilet or bathrooms, including bath tubs and showers if there is reinforcement in the wall provided for future grab bars and seats.

d) Cabinetry shall be permitted under lavatories and kitchen sinks provided that all of the following conditions are met:
(a) the cabinetry can be removed without removal or replacement of the fixture;
(b) the finish floor extends under the cabinetry; and
(c) the walls behind and surrounding the cabinetry are finished.

e) Heights of sinks shall be no higher than 34" max, but in residential dwelling units they can be adjustable heights between 29" minimum and 36" where rough-in plumbing permits connections of supply and drain pipes for sinks mounted at the height of 29".

There are many details within these sections, and we recommend further investigation prior to design or construction.